What is a thunderstorm and how is it formed? Give an account of the different stages in the lifecycle of a thunderstorm. | UPSC MAINS ANSWER WRITING (Q&A)

Q) What is a thunderstorm and how is it formed? Give an account of the different stages in the lifecycle of a thunderstorm.

(Answer in 150 words)

Approach:-

• Briefly explain thunderstorms in the introduction.
• Elaborate on the formation of thunderstorms.
• Discuss the lifecycle of thunderstorms.
• Conclude accordingly.

Answer:-

A thunderstorm is a weather phenomenon characterized by the presence of thunder and lightning.

Formation of Thunderstorm:

There are three ingredients for a thunderstorm to form- moisture, rising unstable air, and a lifting mechanism.

• The sun heats the earth’s surface, which warms the air above it. This warm surface air tends to cause a rising motion.
• The rising air transfers heat to the upper levels of the atmosphere. The water vapour it contains begins to cool, releases the heat, condenses and forms a cloud. The cloud eventually grows upward into areas where the temperature is below freezing.
• As a storm rises into freezing air, different types of ice particles is created from freezing liquid drops. The ice particles grow by condensing vapour (like frost) and by collecting smaller unfrozen liquid drops.
• When two ice particles collide, one particle can rip off a little bit of ice from the other one and grab some electric charge. These collisions build up big regions of electric charges to cause a bolt of lightning, which creates the sound waves (thunder).

Different stages in the lifecycle of a thunderstorm:

Thunderstorms have following three stages in their life cycle:

• Developing stage: This stage is marked by a cumulus cloud being pushed upward by a rising column of air. The cloud soon looks like a tower as the updraft continues to develop. There is little or no rain and occasional lightning.
• Mature stage: The thunderstorm enters the mature stage when the updraft continues to feed the storm, but precipitation begins to fall out of the storm, creating a downdraft. When the downdraft and rain-cooled air spreads out along the ground it forms a gust front. This stage is the most likely time for hail, heavy rain, frequent lightning, strong winds, and tornadoes. Eventually, a large amount of precipitation is produced and the updraft is overcome by the downdraft beginning the dissipating stage.
• Dissipating stage: At the ground, the gust front moves out a long distance from the storm and cuts off the warm moist air that was feeding the thunderstorm. Rainfall decreases in intensity, but lightning remains a danger.

© Image Credit- NOAA, UCAR

Thunderstorms occur mostly in summer months and during the afternoon and evening hours. Under the right conditions, rainfall from thunderstorms causes flash flooding.